Hi all i am re setting an existing tank (2ft), that has a few corys in, I have only ever used playsand in tanks that had corys in, but being fairly new to planting, i had promised myself to do this properly this time round and make sure i used a qaulity substrate, but none of the threads i have looked at or retailers adds say if i can cap the substrates with sand. I did think of using ada aquasoil on its own, but assumed this would make a mess of the water with cory digging about in it, then looked at the tropica stuff but was unsure if i could cap it with sand, and all the gravels i like are a bit sharp. So any and all advise is welcomed. Need something that can be capped with sand, or left uncapped that is suitable for the corys and want turn the water brown when they start digging. ta Karl